Intro to physics? (4)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">intro to physics?</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Another definition for meta that I've seen is " Prefix meaning behind or beyond something".)
(Another definition for astro that I've seen is " Indicates a heavenly body".)